A major function of King’s novel is to interrogate what a monster truly is. While the dog Cujo becomes the central monster in the book (because he has contracted rabies), various monsters exist within its pages: Frank Dodd, abusive men like Joe Camber and Steve Kemp, the monster in Tad’s closet, and even Donna when she brutally kills Cujo. The monstrous in Cujo thus inhabits many forms and occupies many spaces. Monsters straddle naturality and supernaturality throughout the novel. King never definitively describes the link between Frank Dodd, Tadd’s haunted closet, and Cujo but suggests that a supernatural force is at work in the plotline. However, in plotlines like Charity’s struggle to live under the unbearable control of her husband, King emphasizes that monsters exist in our everyday lives as well. By demonstrating the full range of the monstrous, King uses Cujo to show what monsters are, what roles they play in society (both fictional and real), and what they can tell us about ourselves.

In interrogating what constitutes a monster, King allows multiple manifestations of the monstrous throughout the novel. His opening pages on Frank Dodd’s murders and death by suicide immediately establish the mutable form of the monster as an important element in the story: “The monster was gone, the monster was dead.